Groups of persons with increased risk of falls, for example workers on tread surfaces or ladders, firefighting personnel, forestry workers, miners, hospital and nursing care patients, persons with epilepsy, or elderly persons living alone, may receive assistance in the event of a fall when they are monitored for whether they have fallen. The fall may injure persons so severely that they are no longer able to free themselves from an emergency situation or make an emergency call by their own efforts. In addition, a fall without injuries may be an indication of urgent need of treatment, for example in the event of unconsciousness.
Document EP 1 642 248 A1 describes a system for recognizing falls. A system component having a pressure sensor and a motion sensor is worn on the wrist. A second pressure sensor for measuring the air pressure in the dwelling is situated in a base station which receives the air pressure data of the wearable system component.
Document DE 10 2008 049 750 A1 describes a method for recognizing a fall of a person, based on at least one air pressure sensor. As an alternative to adjusting the air pressure sensor worn on the body of the person to a comparative pressure sensor, the option is mentioned of recognizing a fall by evaluating the measured value of the air pressure sensor as a function of time. The expected change in the measured values over time defines a “pattern.” Measured values of the air pressure sensor are evaluated by means of conventional pattern recognition methods.
In conventional methods, falls without a preprogrammed pattern profile may go undetected. Conversely, variations in the weather pattern have a significant influence on the profile of the local air pressure over time, independently of a movement of the person. Even opening windows or doors may bring about numerous pressure gradients, which may trigger a false alarm if they happen to resemble a preprogrammed pattern.